Soil nutrients differ even within one piece of property. A soil test can tell you what additives are necessary for good plant health. One of the most common deficiencies is iron, and, like most problems, it presents itself in the leaves. Liquid iron treatment can be done in soil drenches, leaf sprays and even trunk injection. Experimentation is the only way to see which method will work the best for your situation.
What Is Liquid Iron?
Liquid iron is a concentrate made from ferrous sulfate or chelated iron. It is sold under many brand names, which contain different amounts of iron.
When Is Liquid Iron Needed?
A professional soil test done by a local extension agency is a sure way to diagnose an iron deficiency. Plants in this type of soil will have yellow leaves with dark green veins. Leaves that are completely yellow are likely that way for another reason. Improper watering, insect and disease problems should be ruled out by consulting a plant nursery.
Ways To Apply Liquid Iron
During the growing season liquid iron can be put in a hose-end or pump sprayer and applied to the leaves of a tree or shrub. This type of application works quickly, but it will need to be repeated about once a month.
A liquid iron soil drench is best done in autumn or spring. Pour around the drip line of trees and shrubs. When treating large trees, make holes with an auger or soil probe 2 inches in diameter and 18 inches deep at a few different spots around the drip line. Use a bucket to pour the concentrate in the holes.
Tools for injecting liquid iron directly into tree trunks are available, but they should be used with caution. Most recommend applying during bud-break in early spring. Follow the directions on the label. Water trees well for a few days before and a few weeks after injection. This is a more invasive treatment and there is some risk of decay around the injection site. Do not use topical pruning paints on these places, because they can trap moisture and increase the chances of rot.
Where is Iron Deficiency a Problem?
Areas with alkaline soil are prone to iron deficiencies, as are places which have had topsoil stripped away. Soil with a low organic content or with high phosphorus will cause plants to develop chlorosis. Examples of this are seen where people continually use water-soluble bloom boosters rather than amending the soil with compost.
Certain plants become iron deficient more than others, like Indian hawthorn. Plants like this may be extremely durable in other areas and should not be avoided. Owners should watch the leaves and treat the plant with liquid iron as needed.
Liquid iron will stain concrete and decks. If you spill any, wash the area with fresh water immediately. Be sure to check with utility companies before digging holes in your yard, and avoid puncturing large tree roots with your tools.